1. Field of the Invention
This invention relates to a radio telephone device comprising a base unit connected to a wired circuit and a radio telephone connected to the base unit with a radio circuit, and more particularly, to a device in which a calling function is mutually provided between the base unit and the radio telephone.
2. Description of the Related Art
There is known a multichannel-type radio telephone device which comprises a base unit connected to a wired circuit and a radio telephone connected to the base unit with a radio circuit, and which forms a conversation route between the radio telephone and the wired circuit using a vacant conversation channel among plural conversation channels to make possible conversation between the telephone of the correspondent connected to the wired circuit and the radio telephone.
In such a radio telephone, there is a case, for example, in which, although a call reception in the wired circuit is received at a general telephone provided at the base unit, a person desired by the correspondent is a user of a radio telephone located at a place remote from the base unit. In this case, in a conventional radio telephone device, since it is impossible to call the radio telephone from the base unit, it is necessary to perform a very troublesome operation such that a user of the general telephone provided at the base unit, for example, goes to the radio telephone and notifies the user of the radio telephone of the call reception, and conversation is exchanged by performing an off-hook at the radio telephone.
Similarly, there is also a case in which, although a call reception in the wired circuit is received at the radio telephone, a person desired by the correspondent is a user of the general telephone located at the base unit. In this case as well, in a conventional wired telephone device, since it is impossible to call the base unit from the radio telephone, it is necessary to perform a very troublesome operation such that the user of the radio telephone goes to the base unit and notifies the user of the general telephone provided at the base unit of the call reception, and conversation is exchanged by performing an off-hook at the general telephone.
Accordingly, there is considered a configuration in which a function for transmitting a call signal tone by a switching operation is added to one or both of the base unit and the radio telephone. In this configuration, however, there are problems such that it is only understood that someone is being called at the side of the base unit or the side of the radio telephone, and if there are, for example, two users near the radio telephone, it is impossible to know for whom the call is, and it becomes impossible to secure a private call in practical applications, and the like.
This problem can be solved by adding a conversation function between the base unit and the radio telephone, but such a configuration causes an increase in circuit scale and is therefore not preferable.